Increased nephrotoxicity with ciclosporin, aminoglycosides, amphotericin B, cisplatin, NSAIDs, vancomycin, co-trimoxazole, aciclovir, ganciclovir. Increased risk of hyperkalemia with potassium-sparing diuretics. Increased plasma concentrations and toxicity with azole antifungals, calcium-channel blockers, cimetidine, danazol, HIV-protease inhibitors, macrolide antibacterials and metoclopramide. Antacids, rifampin, rifabutin, casofungin, phenytoin, phenobarbital and carbamazepine decrease tacrolimus plasma concentrations. Concurrent admin of sirolimus and tacrolimus decrease levels of both.